Endoscopes are optical instruments that permit a user to see around or through an obstruction, to see something that would otherwise be concealed. For example, endoscopes are used to permit doctors to see inside a patient""s body without major surgery; some endoscopes require a small access incision to be made in the patients body. Endoscopy systems typically comprise an illumination light source, illumination light guides to conduct the illuminating light to the tissue under observation, imaging optics, and image collection light guides to conduct the image of the tissue to the observer. The image can be detected by the human eye or by an imaging device such as a CCD camera. An imaging device usually employs an image display system such as a CRT monitor to relay the image to the human eye. In some cases, the image detected by the imaging device or camera may be digitized, stored in memory or on media, processed with various software algorithms, and/or then converted to an analog video signal that can be displayed on the image monitor.
Physicians and surgeons use endoscopy devices to examine tissue and decide on treatment. Having a sound basis to compare normal and abnormal tissues is essential. If changes occur in the way the system presents the visual information, the physician""s or surgeon""s ability to interpret results is compromised. To assist accurate diagnosis and treatment, hospitals and clinics must have ways to measure and quantify the performance characteristics of endoscopy devices and of the systems comprising such devices.
Components of endoscopes, and endoscopy systems, can become degraded, or can be incorrectly adjusted, or can fail to operate or otherwise fail to perform. It can be difficult to determine if an endoscope is not performing adequately, particularly where the problem comprises inaccurate color representation. Problems arise from a variety of sources, including difficulties with intensity or spectral characteristics of the illumination lamp or light transmission elements, and bad image sensors, software programs or display systems. Other systems can also fail, such as air, water and suction lines.
Endoscopes typically have problems in one of three areas. First is image quality, which can be defined as the accuracy with which the image viewed by the operator represents the target under observation. In other words, does a straight line stay a straight line when viewed through the endoscope? Second is the photometric quality of an image, which can be defined as the spectral distribution of the light emitted from the target. Third, is the physical integrity of the equipment, particularly the endoscope itself, which can sustain optical damage, leaks or blockages in air and fluid lines and damage to the mechanical control components or envelope.
A variety of approaches have been pursued to remedy these problems. See, e.g., U.S. Pat. Nos. 5,820,547; 5,841,525; xe2x80x9cThe Endo Tester(trademark)xe2x80x94A Lab VIEW-Based Automated Test System for Fiber-Optic Endoscopesxe2x80x9d by Eric Rosow, Hartford Hospital, and Joseph Adam, Premise Development Corporation (brochure); PCT WO 97/07627 (EP0845187 A 19980603); U.S. Pat. Nos. 5,369,481; 5,738,824; WO 98/58682); U.S. Pat. No. 5,494,530.
However, there has gone unmet a need for improved apparatus and methods for assessing the color, image or structural characteristics of an endoscope. The present invention provides these and other advantages.
The present invention provides computer controlled measurement devices, with associated mechanical adapters for connection to various components of endoscopy systems, that measure performance characteristics of an endoscope such as the color, image and structural characteristics. The present invention also provides computer-implemented programming, such as software, for calibrating the measurement devices, collecting and controlling measurements, analyzing measurements or comparing them to established performance criteria. In addition, the systems, devices and methods of the present invention can track previous measurements for a particular endoscope and provide analysis and reports, etc., to identify or describe performance trends and allow a user to plan for replacement or servicing.
In one aspect, the present invention provides a test system able to assess photometric performance characteristics of an endoscope comprising: a photometric measurement module comprising a measurement integrating sphere and at least one adapter able to optically connect the integrating sphere to a plurality of different optical ports of different endoscopes. The photometric measurement module measures data from at least one photometric characteristics selected from the group consisting of absolute optical intensity, relative optical intensity, optical power, optical energy, illuminance, radiance, irradiance, display color, perceived color and transmittance, and a controller containing computer-implemented programming that controls at least one of the calibration, measurement and analysis of the photometric performance characteristics of an endoscope using the data from the module.
In this and other aspects of the invention (unless expressly stated otherwise or clear from the context, all embodiments of the present invention can be mixed and matched), the data are measured over a plurality of discrete wavelengths or wavelength regions, and the system can further comprise an image quality measurement module comprising at least one adapter able to optically connect the module to a plurality of different endoscopes, wherein the module measures data from at least one image quality performance characteristic selected from the group consisting of image size, spatial distortion, contrast, brightness, image resolution, focus and modulation transfer function, and the controller contains computer-implemented programming that controls at least one of the calibration, measurement and analysis of the image quality performance characteristics of an endoscope using the data from the module.
The system can also comprise a structural element measurement module comprising at least one adapter able to operably connect the module to a plurality of different endoscopes, wherein the module measures data of structural element performance characteristic selected from at least one of a mechanical, a pneumatic and a fluidic system of an endoscope, and the controller contains computer-implemented programming that controls at least one of the calibration, measurement and analysis of the structural element performance characteristics using the data from the module.
In some embodiments, the controller controls data acquisition by the photometric measurement module, the image quality measurement module and the structural element measurement module. The controller may track performance trends over time of at least one of the characteristics, respond to a set of operator input instructions to control the data acquisition and analyses of the measurement modules, and calibrate a response of the modules. Calibration can comprise using a reference standard to provide calibration correction factors, and application of the calibration correction factors to the data collected by the photometric measurement module, the image quality measurement module or the structural element measurement module provide a corrected data set. The computer-implemented programming may also provide for acquisition and storage of a background signal data set; acquisition and storage of a measurement signal data set representing raw data obtained from the sample device; and, subtraction of the background signal data set from the measurement signal data set to generate a background corrected measurement data set.
If desired, the programming can apply the calibration correction factors to the background corrected measurement data set to generate a calibrated measurement data set. It may also analyze the background corrected measurement data set to determine if the background corrected measurement data set is of acceptable quality to provide an acceptable background measurement data set and provides an indicator to the operator if the background corrected measurement data set is not of acceptable quality, and analyze the background corrected measurement data set with the calibration measurement data set and provides an indication of a performance characteristic for at least one of the characteristics based on the background corrected measurement data set with the calibration measurement data set. The programming may determines whether the performance characteristic is within an acceptable range. The performance characteristic, and other data and programming, can be recorded in a computer-readable memory, for example recording the performance characteristic can provide a recorded measurement data set.
The programming additionally compares and analyzes a performance characteristic from a recorded measurement data set and at least one additional performance characteristic from a different time to determine a temporal trend, which can, as with the other data, analyses, results and other information related to the system, be indicated to the user. The programming may analyze the data obtained from the modules to determine if the data comprises an acceptable signal level and if not then adjust data acquisition until the acceptable signal level is obtained.
In preferred embodiments, the structural element measurement module comprises a pressure transducer and a flow meter, and the adapter operably connects the structural element measurement module to an endoscope to transfer a gas, a liquid or a vacuum between the structural element measurement module and the endoscope. The photometric measurement module preferably comprises a spectrometer comprising a wavelength dispersive element optically connected to the measurement integrating sphere. The at least one adapter may comprise a set of removable adapters able to optically connect to a plurality of light-emitting ports of a plurality of different endoscopes; the removable adapters comprise a flexible fiber optic or a liquid light guide. The system preferably comprises an illumination light source having a known spectral distribution and an illumination integrating sphere optically connected to the illumination light source, for example by a flexible fiber optic, a liquid light guide, a condenser lens assembly, a mirror or a prism.
In certain embodiments, the mating surface of the removable adapters that mates with an interior surface of the integrating sphere comprises a curvature that substantially matches the curvature of the interior surface, such that the mating surface lies substantially flush with the interior surface. The removable adapter can comprise a first mating surface sized to a the first integrating sphere and a second mating surface sized to fit a second integrating sphere.
The image quality measurement module comprises a linearly arrayed sensing element such as a line scan CCD detector and a linear diode array. The linearly arrayed sensing element may be translated or rotated relative to a conjugate image plane of the endoscope to make at least one measurement in the conjugate image plane, or vice-versa, and the programming can reconstruct a sequence measurements of in the conjugate image plane to create a two-dimensional digital image of the conjugate image plane.
In another aspect, the present invention provides a photometric measurement system comprising an integrating sphere optically connected to a receive light from a measurement probe sized that is shaped to receive light from an image display screen, the integrating sphere further optically connected to transmit light to a photometric measurement device comprising a spectrometer comprising a wavelength dispersive element, wherein the photometric measurement system is operably connected to a controller containing computer-implemented programming that responds to a set of operator input instructions to control the data acquisition and analyses of the photometric measurement system and that controls measurement of the image display screen. In certain embodiments, the image display screen is operably connectable to an endoscope to display an image transmitted from the endoscope. The image display screen can be operably connectable to a signal generator able to generate a plurality of test signals on the image display screen.
In a further aspect, the present invention provides a photometric system to assess optical characteristics of a light source, the system comprising a photometric measurement module comprising a measurement integrating sphere and at least one light collector sized and shaped to transmit substantially all wavelengths of UV, visible and NIR light from the sample light source to the integrating sphere, the measurement integrating sphere optically connected to transmit substantially all wavelengths of UV, visible and NIR light from the measurement integrating sphere to a photometric measurement device that is able to measure substantially all wavelengths of UV, visible and NIR light. The photometric measurement module is operably connected to a controller containing computer-implemented programming that responds to a set of operator input instructions to control the data acquisition and analyses of the photometric measurement module and that controls measurement and analysis of the sample light source. In certain embodiments, the light collector is sized and shaped to transmit light from an endoscopic light source, and the system can further comprise an adapter to transmit light from the sample light source through the endoscope upstream of the measurement integration sphere.
In still a further aspect, the present invention provides a test and measurement system able to assess performance characteristics of an endoscope comprising a all three of a photometric measurement module (with or without an integration sphere), an image quality measurement module, a structural element measurement module, and related programming.
In still yet another aspect, the present invention provides a removable adapter having a first end and a second end, the first end defining a mating surface that mates with an interior surface of an integrating sphere and comprising a substantially spherical curvature that substantially matches a curvature of the interior surface, such that the mating surface lies substantially flush with the interior surface when the removable adapter is mated with the integrating sphere, and the second end defining a port sized and shaped to optically connect the integrating sphere to a sample device. The present invention also provides an integrating sphere system comprising such a removable adapter
In another aspect, the present invention provides a test system comprising an image quality measurement module and a detector comprising a linearly arrayed sensing element. The linearly arrayed sensing element can be a one-line sensor, a three-line sensor or other suitable design. Also, the integrating sphere can comprising at least two optical input ports sized and shaped to optically connect the integrating sphere to at least an equal plurality of different optical ports of an endoscope.